通过控制条件来考察自变量和因变量之间的因果关系的研究方法是（）。
A.实验法
B.调查法
C.测验法
D.观察法
参考答案：A
由DIC引起的贫血属于（）
A.失血性贫血
B.缺铁性贫血
C.中毒性贫血
D.再生障碍性贫血
E.溶血性贫血
Scope definition is ______ .
A．the process of developing a detailed project scope statement as the basis for future project decisions
B．determining the responses needed to perform project activities
C．analysis of activity sequence, duration, and resource requirements
D．a written statement identifying the quality standards relevant to the project
